Weidmuller TWI-1 - Signal isolator in 2-wire design, 1-channel - Handbuch (Seite 9)


en TWI-1
•Operation
general
The TWI-1 is a DIN rail mount, loop powered, signal Isolator/Converter
for current/voltage signals.
Loop powered transmitters use the drop in voltage across the outputs
to generate power for the electronics. The TWI requires at least a 1 V
drop to operate correctly.
Receiving devices are placed in series with the TWI and introduce
additional load resistances into the loop. The total loop load for a
4-0 mA loop powered by supply voltage V
s
is R
loop
= 50 x (V
s
-1).
So, for example, a TWI powered from a 4 V DC supply can drive
600 Ω loop load.
Cleaning
The case can be wiped with a damp cloth. De-energise the unit before
cleaning.
Receiving
device
(Current
inputs)
Power
Supply
− +
Twisted pair cable
Loop
Powered
Transmitter
– + + −
Connection diagram for loop powered transmitter outputs.